High-frequency forcing of a turbulent axisymmetric wake

A high-frequency periodic jet, issuing immediately below the point of separation, is used to force the turbulent wake of a bluff axisymmetric body, its axis aligned with the free stream. It is shown that the base pressure may be varied more or less at will: at forcing frequencies several times that of the shear layer frequency, the time-averaged area-weighted base pressure increases by as much as 35 %. An investigation of the effects of forcing is made using random and phase-locked two-component particle image velocimetry (PIV), and modal decomposition of pressure fluctuations on the base of the model. The forcing does not target specific local or global wake instabilities: rather, the high-frequency jet creates a row of closely spaced vortex rings, immediately adjacent to which are regions of large shear on each side. These shear layers are associated with large dissipation and inhibit the entrainment of fluid. The resulting pressure recovery is proportional to the strength of the vortices and is accompanied by a broadband suppression of base pressure fluctuations associated with all modes. The optimum forcing frequency, at which amplification of the shear layer mode approaches unity gain, is roughly five times the shear layer frequency

Periodic Forcing of a Turbulent Axisymmetric Wake

Effects of variable-frequency forcing. Relation to linear theory. Effects of three-dimensional forcing. Relation between instability mechanisms. Future work includes open-loop control and feedback control

Planning southern Iraq: placing the progressive theories of Max Lock in Um Qasr, Margil, and Basra in the context of Iraqi national development, 1954–1956

Between 1954 and 1956, the architect, educator, and planner, Max Lock (1909–1988) produced a trilogy of plans to modernize the historical city of Basra and create new areas at Margil and Um Qasr in the south of Iraq. The New Basrah Plan was heavily inspired by the works of Patrick Geddes and aligned with contemporaries such as Lewis Mumford, Lock’s planning was progressive in scope and looked to differ from the planning of post-war principles in Britain through his notions of ‘civic surgery’. Contrary to this, his plans for Um Qasr and Margil focussed on infrastructure and the creation of more industrial areas not prioritizing people and place as highly as he did in the New Basrah Plan. Lock’s ‘Civic Surgery’ offered an alternative to mainstream thought by attempting to create usable, humanistic spaces, which hampered by politics and legislation, resulted in the plan’s shelving and were contradicted by his other works’ philosophies. New retrospective analysis of his underappreciated career reveals the complexities of his planning which this article demonstrates through the ‘failure’ of the New Basrah Plan and his plans at Um Qasr and Margil

Active control of a turbulent bluff body wake

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Estatus Actual de los Búhos Terrestres (Athene cunicularia) en la Zona de Puerto López, Ecuador: Efectos de las Creencias y Sentimientos hacía los Animales Silvestres

In response to negative attitudes towards the existing biodiversity in the region of Puerto Lopez, Ecuador and as a follow-up of a study conducted in 2006 on the status of Burrowing Owl (Athene cunicularia) populations, through informal interviews and observation, this investigation focuses on how local sentiments towards nature have affected the current status of the Burrowing Owl populations and their habitat. The investigation revealed that in addition to the effects of legends and beliefs, there is an existing lack of knowledge, understanding, and appreciation for the extremely high biodiversity, which has created an evident fear instilled in the people. In result, the attitudes towards wildlife have lead to destruction and have greatly impacted the populations and habitats of the Burrowing Owls. During the project, it was observed that it is possible to change negative attitudes towards nature and wildlife, although, because of the need for understanding and appreciation of the natural life in Puerto Lopez, I made some learning materials about Burrowing Owls that will be used for environmental education. In the efforts of conservation of wildlife and nature in Puerto Lopez, the most important force will be to spread knowledge about the biodiversity in order to eliminate the existing fear. Como seguimiento a un estudio anterior y en base a algunas observaciones de sentimientos negativos hacia los animales silvestres en el cantón Puerto López, Ecuador, por medio de entrevistas y observaciones, investigué las actitudes de la gente hacía los animales silvestres, específicamente los Búhos terrestres (Athene cunicularia). También, observé el estatus actual de las poblaciones y hábitat de Búhos terrestres y cómo están afectados por los sentimientos de la gente de la zona. Durante el proyecto, descubrí, en general, un gran miedo hacía los animales silvestres en la región, un miedo fundado en creencias, tradiciones, y una falta de conocimiento de la biodiversidad. Como resultado, estos sentimientos han afectado mucho el estatus actual de las poblaciones de Búhos terrestres, especialmente sus hábitats. Además, dejo algunos materiales didácticos sobre los Búhos terrestres que van a servir para educación ambiental. Pueden ayudar a inculcar en los niños el reconocimiento y aprecio de la gran biodiversidad que les rodea en Puerto López porque esta actitud es lo más importante para los esfuerzos de conservación de los Búhos terrestres y otros animales silvestres

Active control of a turbulent bluff body wake

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A Guide for Schools: Understanding and Working with Parents of Transgender Students

This dissertation fills a gap in the literature on supporting transgender students through a school-family partnership. Lack of support at home and school is directly correlated with LGBTQ students’ heightened risks of mental illness, contraction of HIV, incarceration, homelessness, and academic problems (Bontempo & D’Augelli, 2002; Goodenow, Szalacha, & Westheimer, 2006). Family support and acceptance helps to protect transgender youths from these negative outcomes (Bockting et al., 2013; Ryan et al, 2010; Ryan, 2009). Parents can be more effective at supporting their transgender children if they are provided with “a knowledgeable source for guidance, accurate information, and support” (SAMHSA, 2014, p. 2). School professionals are positioned at the intersection of schools and families and, as such, have the opportunity to serve as that much-needed source. However, no synthesized guidelines exist at this time to guide school professionals in their work with parents of transgender students. The purpose of this dissertation is to synthesize scattered recommendations into a single guide for school professionals to understanding and working with the parents of transgender students. This understanding of transgender students’ development, their parents, and their schools is anchored in Bronfenbrenner’s (1979) bioecological model of human development, with steps towards an effective school-family partnership framed as mesosystem interventions